Book Image

Learning Java by Building Android Games - Second Edition

By : John Horton
Book Image

Learning Java by Building Android Games - Second Edition

By: John Horton

Overview of this book

Android is one of the most popular mobile operating systems presently. It uses the most popular programming language, Java, as the primary language for building apps of all types. However, this book is unlike other Android books in that it doesn’t assume that you already have Java proficiency. This new and expanded second edition of Learning Java by Building Android Games shows you how to start building Android games from scratch. The difficulty level will grow steadily as you explore key Java topics, such as variables, loops, methods, object oriented programming, and design patterns, including code and examples that are written for Java 9 and Android P. At each stage, you will put what you’ve learned into practice by developing a game. You will build games such as Minesweeper, Retro Pong, Bullet Hell, and Classic Snake and Scrolling Shooter games. In the later chapters, you will create a time-trial, open-world platform game. By the end of the book, you will not only have grasped Java and Android but will also have developed six cool games for the Android platform.
Table of Contents (30 chapters)
Learning Java by Building Android Games Second Edition
Contributors
Preface
Index

The Soundpool class


The SoundPool class allows us to hold and manipulate a collection of sound FX; literally, a pool of sounds. The class handles everything from decompressing a sound file like a .wav or a .ogg, keeping an identifying reference to it via an integer id and of course, playing the sound. When the sound is played it is done so in a non-blocking manner (using a thread behind the scenes) that does not interfere with the smooth running of our game or our user's interaction with it.

The first thing we need to do is add the sound effects to a folder called assets in the main folder of the game project. We will do this for real shortly.

Next, in our Java code, declare an object of type SoundPool and an int identifier for each and every sound effect we intend to use. We also declare another int called nowPlaying which we can use to track which sound is currently playing and we will see how we do this shortly.

// create an identifier
SoundPool sp;
int nowPlaying =-1;
int idFX1 = -1;
float...